From 2e43fbbf55d2532866cd132e2c9b3a9c72169973 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carl=20H=C3=B6rberg?= <carl@84codes.com>
Date: Fri, 8 Sep 2023 14:15:43 +0200
Subject: [PATCH] Unmap segments when all consumers has disconnected from a
 queue

---
 src/lavinmq/queue/message_store.cr              |  8 ++++++++
 src/lavinmq/queue/queue.cr                      | 10 ++++++++--
 src/lavinmq/queue/stream_queue_message_store.cr |  8 --------
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/lavinmq/queue/message_store.cr b/src/lavinmq/queue/message_store.cr
index fd74c0b92b..23a93f3c8f 100644
--- a/src/lavinmq/queue/message_store.cr
+++ b/src/lavinmq/queue/message_store.cr
@@ -208,6 +208,14 @@ module LavinMQ
         (@bytesize / @size).to_u32
       end
 
+      def unmap_segments(except : Enumerable(UInt32) = StaticArray(UInt32, 0).new(0u32))
+        @segments.each do |seg_id, mfile|
+          next if mfile == @wfile
+          next if except.includes? seg_id
+          mfile.unmap
+        end
+      end
+
       private def select_next_read_segment : MFile?
         # Expect @segments to be ordered
         if id = @segments.each_key.find { |sid| sid > @rfile_id }
diff --git a/src/lavinmq/queue/queue.cr b/src/lavinmq/queue/queue.cr
index 7b6fbbd380..8271bb07aa 100644
--- a/src/lavinmq/queue/queue.cr
+++ b/src/lavinmq/queue/queue.cr
@@ -831,8 +831,14 @@ module LavinMQ
         end
       end
       if @consumers.empty?
-        notify_consumers_empty(true)
-        delete if @auto_delete
+        if @auto_delete
+          delete
+        else
+          notify_consumers_empty(true)
+          @msg_store_lock.synchronize do
+            @msg_store.unmap_segments
+          end
+        end
       end
     end
 
diff --git a/src/lavinmq/queue/stream_queue_message_store.cr b/src/lavinmq/queue/stream_queue_message_store.cr
index 918e554371..0226e38ced 100644
--- a/src/lavinmq/queue/stream_queue_message_store.cr
+++ b/src/lavinmq/queue/stream_queue_message_store.cr
@@ -16,14 +16,6 @@ module LavinMQ
         drop_overflow
       end
 
-      def unmap_segments(except : Enumerable(UInt32))
-        @segments.each do |seg_id, mfile|
-          next if mfile == @wfile
-          next if except.includes? seg_id
-          mfile.unmap
-        end
-      end
-
       private def get_last_offset : Int64
         return 0i64 if @size.zero?
         bytesize = 0_u32